Pipe hanging apparatus



Aug. 8, 1967 w. 1.. TODD 3,334,924

' PIPE HANGING APPARATUS Filed July 9. 1963 s Sheets-Sheet 1 'F'IE 1 INVENTOR WILLIAM L. TODD e MM Pia/W.

ATTORNEY Aug- 8, 1967 w. TODD 3,334,924

PIPE HANGING APPARATUS Filed July 9, 1963 6 Sheets-Sheet 2 INVENTOR WILLIAM L. TODD ATTORNEY Aug. 8 1967 w. L. TODD 3,334,924

PIPE HANGING APPARATUS Filed July 9, 1963 6 Sheets-Sheet 4 BY M fi ml uzJ.

' ATTORNEY INVENTOR WILLIAM TODD 6 w. 1.. TODD 3,334,924

NNNNNN O R LLLLLLLLLLL OD Aug. 8,1967 w. L. TODD PIPE HANGING APPARATUS 6 Sheets-Sheet 6 Filed July 9, 1963 0pm mmN m L w omw wwm OWN Nw mPN mm L INVENTOR WILLIAM L. moo

BY A9444 ATTORNEY United States Patent M 3,334,924 PIPE HANGING APPARATUS William L. Todd, Houston, Tex., assignor to FMC Corporation, San Jose, Calif, a corporation of Delaware Filed July 9, 1963, Ser. No. 293,818 25 Claims. (Cl. 28518) The present invention pertains to a well apparatus and more particularly to a remotely controllable pipe hanging mechanism.

Mechanism embodying the subject invention is especially suited for use in completing underwater wells, and it is described in this environment. It will be understood, however, that the invention is not limited to underwater wells.

One of the tasks of completing an underwater well is that of hanging casing within the wellhead. Probably the simplest way to hang the casing is with a mandrel hanger that is connected to the casing and landed on a seat in the wellhead, but sometimes the casing sticks and cannot be lowered far enough to land the mandrel hanger. Under these circumstances an alternative hanger must be employed. Thus, the mechanism disclosed herein includes a contractible pipe-hanger that is in a diametrically expanded retracted position Within the wellhead while drilling operations are being carried on through the wellhead.

The use of such a hanger in the above described manner presents certain problems. First, the hanger must be protected against damaging contact by the drill bit and drill string during the drilling operations. Secondly, when it is desired to hang the casing, the hanger must be moved into casing hanging position preferably by remote control to minimize installation time and to obviate the need for divers. Thirdly, the hanger must be dependably retained in a casing hanging position after it is moved into such a position. The present invention solves all of these problems.

Accordingly, it is an object of the present invention to provide a remotely controllable pipe hanging mechanism for a well apparatus.

Another object is to provide a pipe hanging mechanism that has a diametrically expanded pipe hanger capable of being contracted around a string of pipe.

Another object is to provide a pipe hanging mechanism of the type described that protects the hanger in its expanded position.

Another object is to provide a pipe hanging mechanism of the type described that moves the hanger into a contracted, pipe hanging position by remote control.

Another object is to provide a pipe hanging mechanism that dependably retains the hanger in its pipe hanging position after it is moved into such position.

Another object is to provide a pipe hanging mechanism including a contractible pipe hanger, a hanger protecting sleeve, and a hanger retaining mandrel wherein, by remote control and sequentially, the sleeve is moved from a hanger protecting position to a position exposing the hanger, the hanger is moved from a retracted position to its pipe hanging position, and the mandrel is projected from a retracted position into a hanger retaining position.

Another object is to provide a pipe hanging mechanism that supports a contractible pipe hanger in retracted position but which is operable under application of fluid pressure to guide the hanger into a contracted hanging posi-' tion.

Another object is to provide a pipe hanging mechanism including a fluid control system for sequentially and automatically operating the protecting sleeve, the pipe hanger, and the retaining mandrel.

These together with other objects will become apparent upon reference to the following description and accompanying drawings in which:

3,334,924 Patented Aug. 8, 1967 FIGURE 1 is a fragmentary side elevation of a well apparatus including a pipe hanging mechanism embodying the present invention.

FIGURE 2 is an enlarged fragmentary diametrical vertical section of the apparatus illustrated in FIG. 1 and shows a slip hanger and its retaining mandrel in retracted positions and a hanger protecting sleeve in its protecting position.

FIGURE 3 is a view similar to FIG. 2 but shows the slip hanger in its hanging position in engagement with a casing, the sleeve in its retracted position, and the mandrel in its retaining position.

FIGURE 4 is an enlarged view of a portion of the apparatus shown in FIG. 2.

FIGURE 5 is a transverse section taken on line 55 in FIG. 2.

FIGURE 6 is a diagrammatic view of a fluid control system employed in the subject mechanism.

FIGURE 7 is a longitudinal section through a check valve employed in the fluid control system illustrated in FIG. 6.

Before describing the subject mechanism 9 (FIG. 1) in detail, it will aid understanding to note (FIG. 2) that the disclosed mechanism provides a hanger protecting sleeve 10, a slip hanger 11 including plurality (four in the disclosed embodiment) of hanger units 12, and a hanger retaining mandrel 197, all mounted within a wellhead 16, or the like. While drilling and before hanging an inner string 310 of casing, the hanger units are retracted and are protected against damage by the sleeve, as shown in FIG. 2. When it is desired to hang the casing string, an operator at a remote location, usually at the surface of the water above the well, causes fluid pressure to be applied to the mechanism whereby, in succession and automatically, the sleeve is moved to a retracted position (FIG. 3) to expose the hanger units, the units are moved into casing hanging positions, and the mandrel is moved into a retaining position between the units and the wellhead.

With reference to FIG. 1, the mechanism 9 is incorporated in a well apparatus that includes a lower casinghead assembly 20 cemented in place adjacent to the ocean floor 21 and supporting an outer casing string 23 in a borehole 24. Guide system brackets 26 are attached to the casinghead assembly and project upward therefrom. The apparatus also includes the wellhead "16 which has a lower end portion 30 seated on the casinghead assembly, an upper end portion 31, and a passageway 32 extending axially through the wellhead.

The wellhead 16 (FIG. 2) includes a lower, cylindrical chamber wall 36, a radial lower abutment 38, a cylindrical lower guide wall 40, a lower frusto-conical seat 42 diverging upward from the lower guide wall, and a cylindrical intermediate wall 44 projecting up from the lower seat and having a diameter greater than the diameter of the lower chamber wall. The wellhead also has a radial shoulder 46 projecting in from the intermediate wall, a cylindrical upper chamber wall 48 projecting up from the shoulder, a radial upper abutment 50 extending in from the upper chamber wall, an internally threaded wall 52, a radial surface 54, a cylindrical upper guide wall 56 extending up from the radial surface, an upper frusto-conical seat 58 diverging up from the upper guide wall, and an upper end wall 60.

The protecting sleeve 10 (FIG. 2) has a lower enlarged portion 70 that is slidably fitted in the lower chamber wall 36 and a shank 72 projecting up from the lower portion and slidably fitted in the lower guide wall 40. The shank has an upper end edge 73 and an external annular groove 74 in adjacent spaced relation to saidupper end edge. The lower portion of the sleeve provides an annular shoulder 76 confronting the lower abutment 38, and an O-ring 78 encircles this lower portion in sealing, sliding engagement with the lower wall 36.

It is to be noted that the wellhead 16 (FIG. 2) has an annular inlet channel 80 surrounding the passageway 32 and spaced radially outward therefrom. Further, the wellhead provides a plurality of radial inlet holes 82 extending from this channel to the passageway, an inlet duct 84 extending from the channel to the exterior of the wellhead, and an outlet duct 86 (FIG. 4) having an annular mouth 88 (FIGS. 2 and 4) opening into the passageway above the inlet holes and an outer end 90 opening to the exterior of the wellhead. Upper and lower seal rings 92 are fitted in grooves in the wellhead above and below the mouth 88, in surrounding relation to the passageway, and in sliding, sealing engagement with the shank 72 of the sleeve 10. In addition, an O-ring 93 is provided in the wellhead in surrounding relation to the passageway and just below the lower seat 42; this O-ring is provided to prevent fluid leakage through a path that results from the manner of constructing the wellhead.

The protecting sleeve 10 is mounted within the wellhead 16 for movement between an upper protecting position (FIG. 2) wherein the shank 72 is circumferentially spaced from the intermediate wall 44 thereby to provide an annulus 96 and a lower exposing position (FIG. 3) wherein the upper end edge 73 of the shank is spaced below the lower seat 42 and wherein the groove 74 bridges the lower seal ring 92 and establishes fluid comrnunication between the radial inlet holes 82 and the mouth 88 of the outlet duct 86. In the protecting position of the sleeve (FIG. 2), the shoulder 76 is in engagement with the lower abutment 38 whereas in the exposing position (FIG. 3), this shoulder is spaced below the abutment so that an annular lower fluid chamber 98 is provided by the sleeve, the lower chamber wall 36, the shoulder, and the abutment. Shear pins 99 (FIG. 2) project from the wellhead into the lower portion 70 of the sleeve and releasably retain it in its protecting position. Plugs 99' are threaded into the shear pin holes inward of said pins. A stop ring 100 is mounted in the lower chamber wall 36 and limits downward movement of the sleeve, as best illustrated in FIG. 3.

The wellhead 16 also has a plurality of substantially equally, circumferentially spaced transverse bores 110 (FIGS. 2 and 4) having axes obliquely related to the axis of the passageway 32. The number of bores corresponds to the number of hanger units 12 that are employed. The bores open into the passageway above the lower seat 42. The subject mechanism 9 includes fluid operated hanger actuators 112 (FIGS. 2, 4 and individually mounted in the bores 110. Each actuator (FIG. 4) provides a cylinder 114 having a tube 115 fitted in its respective bore 110. Each tube has an enlarged inner portion 117 relatively adjacent to the passageway 32, a diametrically reduced intermediate portion 119 that is circumferentially spaced from the bore wall 111 so as to provide an annular fluid conducting space '120, and an outlet port 122 extending through the intermediate portion in adjacent spaced relation to the inner portion 117. Each cylinder also has an outer block 124 including an annular internally threaded flange 126 integral with said intermediate portion 119 and connected by a bolt 127 to the wellhead 16; this flange has an outlet passage 128 communicating with the annular fluid conducting space 120. An O-ring 129 is fitted in an annular groove in the flange, outward of the passage 128, and seals against the wellhead around the bore 110. The block also includes a cap 130 screwed into the flange and provided with an internal shoulder 131 circumscribing an inlet bore 132 extending axially through the cap. An O-ring 124 encircles the inner portion 117 of the tube and seals between the wellhead 16 and cylinder. An O-ring 136 encircles the cap and provides a seal between the cap and the intermediate portion 119 of the tube.

Each actuator 112 (FIG. 4 )also includes a generally cylindrical piston 140 slidably fitted in the inner portion 117 of the cylinder 114. Each piston has an inner end portion 142 projecting into the passageway 32 and an outer end portion 143 projecting into the intermediate portion 119 of the cylinder; the outer end portion terminates in an enlarged head 144. A frangible screw 146 has a solid inner portion 148 threaded into the outer end portion of the piston and enlarged outer coupling portion 150 fitted in the inlet bore 132 of the cap and precluded from moving all the way through the inlet bore by engagement with the shoulder 131 in the cap. The outer portion of the screw has an axial duct 152, and this duct has an outer end opening into the inlet bore and an inner end closed by the solid portion of the screw. An annular lip seal 154 is fitted in the inner portion 117 of the tube and is in surrounding slidably sealing engagement with the piston. This lip seal allows fluid moving inward along the piston to travel therepast but precludes movement therepast of fluid moving outward along the piston. An O-ring 156 surrounds the head 144 of the piston and is in slidably sealing engagement with the intermediate portion 119 of the cylinder.

The hanger actuators 112 are normally retained in retracted positions (FIGS. 2 and 4) by the frangible screws 146; in these retracted positions, the pistons are held within the cylinders 114. Upon application of suflicient fluid pressure in the inlet bores 132, the inner solid portions 148 break away from the outer coupling portions of the screws whereupon the pistons are thrust inwardly into projecting positions (FIG. 3) wherein the heads 144 of the pistons engage the inner portions 117 of the cylinders to limit inward movement of the pistons, and wherein the outlet ports 122 establish fluid communication between the inlet bores 132 and their respective outlet passages 128; that is, in the projecting positions of the pistons, the heads of the pistons are spaced inward of the outlet ports so that these outlet ports establish fluid communication between the annular spaces 120 and the interiors of the intermediate portions 119 of the cylinders on the pressure sides of the pistons. During the projecting strokes of the pistons, fluid between the piston heads and the inner portions 117 of the cylinders escapes past the lip seals 154 thereby preventing build-up of pressure in front of the projecting piston heads.

The hanger units 12 of the slip hanger 11 are individually mounted on the actuators 112 for movement with the pistons 140. The hanger units (FIG. 2 and 5) are arcuate and concentric with the passageway 32, and each unit includes a lower junk ring segment 160 (FIG. 2) fitted on the inner end portion 142 of an associated piston 140 and connected thereto by a bolt 162 coaxial with the piston. This segment has an outer bevelled edge 164 slidably engaging the lower seat 42 in the wellhead 16. Each hanger unit also includes a resiliently compressible and expansible seal 166, preferably of rubber, lying on the junk ring segment, a rigid thrust ring segment 168 overlying the seal, a bowl segment 170 rested on the thrust ring segment, and a slip 172 mounted on the bowl. Screws 174 are extended through a slot 176 in the slip and are threaded into the bowl segment thereby mounting the slip on the segment for downward slidable movement thereon. A shear pin 178 releasably interconnects the bowl segment and the slip and holds the slip in an upper position. In each unit, a bolt 180 (FIG. 4) extends upward through the junk ring segment, the seal, the thrust ring and the bowl segment for maintaining the unit in an assembled relation.

The slip units 12 are movable from outer retracted positions (FIG. 2) wherein they are in circumferentially spaced relation to each other (FIG. 5) to inner casing hanging positions (FIG. 3) wherein adjacent units are in engagement. In the outer positions of the units, the slip hanger 11 is thus diametrically expanded whereas in the inner casing hanging positions, the slip hanger is diametrically contracted. It is believed understood that the hanger units move from their outer to their inner positions when the pistons 140 are thrust inwardly upon introduction of fluid pressure through the inlet bores 132. Further, the hanger units are supported on the lower seat 42 in both their outer and their inner positions. In the inner positions of the hanger units, the bowl segments 170 collectively provide an outer frusto-conical mating surface 171.

The hanging mechanism 9 also includes an upper guide sleeve 185 mounted within the passageway 32. The guide sleeve has an upper end 186 threaded into the wall 52 of the wellhead 16 and a lower edge 187 overlapping the upper end edge 73 of the protecting sleeve 10 when the latter is in its protecting position (FIG. 2). An O-ring 189 encircles the upper end of the guide sleeve and is in fluid sealing engagement with the wall 52.

A plurality of guide rods 195 have upper ends threaded into the upper abutment 50 of the wellhead 16 and extend downward in circumferentially spaced relation about the passageway 32. The annular hanger retaining mandrel 197 is slidably fitted within the upper chamber wall 48 of the wellhead and provides a plurality of bores 198 slidably receiving the guide rods. The mandrel has an upper annular end face 199 confronting the upper abutment 50, a lower annular end face 201, an outer cylindrical surface 203 slidably engaging the upper chamber wall 48, an upper inside cylindrical surface 204, an intermediate frusto-conical mating surface 206 and a lower inside cylindrical surface 208. The lower end face of the mandrel provides a plurality of notches 210 vertically aligned with the pistons 140. Inner and outer O-rings 212 are fitted in grooves in the upper inside cylindrical surface 204 and the outer cylindrical surface 203 and are respectively in slidable sealing engagement with the guide sleeve 185 and with the upper chamber wall 48.

The retaining mandrel 197 also has a plurality of circumferentially spaced, radially outwardly opening pockets 220 in adjacent spaced relation to the upper end face 199. Latching dogs 222 are slidably fitted in these pockets, and compression springs 223 are positioned between shoulders 224 on these dogs and the mandrel and yieldably urge the dogs into positions projecting outward from the outer surface 203 of the mandrel. The mandrel is movable from an upper retracted position, (FIG. 2) wherein the lower end face 201 of the mandrel is above the hanger units 12 and wherein the dogs 222 are urged against the upper chamber wall 48 but are retracted within the pockets, to a lower hanger retaining or looking position (FIG. 3). In this retaining position, the notches 210 are fitted over the pistons 40; the lower cylindrical surface 208 is in, engagement with the seals 166, the thrust ring segments 168 and the lower portions of the bowl segments 170 of the hanger units 12 in their hanging positions; the mating surface 206 of the mandrel is in engagement with the mating surface 171 of the slip hanger 11; and the dogs 222 are projected under the radial shoulder 46 of the wellhead 16 in latching positions. Shear pins 230 extend from the upper chamber wall 48 into the mandrel 197 above the O-rings 212 for releasably holding the mandrel in its retracted position, and plugs 232 are threaded in the shear pins holes outward of the pins. Furthermore, the wellhead 16 has an upper inlet duct 235 that opens, immediately below the upper abutment, into an upper chamber 237, the latter being defined by the guide sleeve 185, the mandrel 197, the upper chamber wall 48, and the upper abutment 50. The shear pins hold the mandrel in its retracted position so that the upper end face 199 is slightly spaced from the upper abutment whereby fluid entering through the inlet duct can exert pressure on the upper end face of the mandrel. It is also to be noted that holes 240 are provided in the wellhead 16 in alignment with the dogs in their latching positions; these holes are provided so that the dogs can be retracted during installation of the mandrel. Thereafter these holes are plugged.

The subject pipe hanging mechanism 9 also includes a fluid control system illustrated diagrammatically in FIG. 6. This system provides a reservoir 250, a pump 252 having an inlet connected to the reservoir and an outlet connected to a main control valve 254, a main supply line 256, an actuator control valve 258 and mandrel control valves 259, 260, 261 and 262.

Each of the actuator and mandrel control valves 258 262 is mounted on the wellhead 16 and includes a valve body 265 (FIG. 7) providing an internal seat 266 and a ball 267 normally but releasably held against the seat by a compression spring 268 mounted in a cap 270. The body has a main inlet 272 that communicates with an outlet 273 through the seat when the ball is forced away from the seat. The body also has a pilot inlet 275 that leads into a cylinder 278 in which is positioned a piston 279. A piston rod 280 has one end connected to the piston and an opposite end engaging the ball 267 on the opposite side thereof from the spring 268. Furthermore, the body has an exhaust port 282 establishing communication between the cylinder, on the opposite side of the piston from the pilot inlet, and the amosphere. In operation of the valve, when appropriate pressure is applied in the cylinder through the pilot inlet, the piston rod forces the ball away from the seat and establishes communication between the main inlet and the outlet. The valve thus has a closed position (FIG. 7) with the ball in the seat and an open position (not shown) with the ball spaced from the seat.

With reference again to the entire fluid system (FIG. 6), the main supply line 256 is connected to the lower inlet duct 84 of the wellhead 16, and a branch supply line 290 is connected from this main supply line to the main inlet 272 of the actuator control valve 258. The outer end 90 of the outlet duct 86 in the Wellhead is connected to the pilot inlet 275 of the actuator control valve by a bypass line 292. A main outlet line 296 connects the outlet 273 of the actuator control valve to the inlet bores 132 of each of the cylinders 114 by branch lines 298, whereas a branch line 299 connects this main outlet line to the main inlet 272 of the first mandrel control valve 259. Each cylinders outlet passage 122 is connected by a by-pass line 302 to the pilot inlet 275 of the associated mandrel control valve 259462; it is to be noted in FIG. 6 that the by-pass line 302 is connected directly to the outlet port 122, for simplicity of illustration in this diagrammatic view, although in an actual embodiment, line 302 would be connected as shown in FIGS. 2, 3 and 4. The outlets 273 of the first, second, and third mandrel control valves are connected respectively to the main inlets 272 of the second, third, and fourth mandrel control valves by connecting lines 304. Finally, a coupling line 306 interconnects the outlet of the fourth mandrel control valve 262 and the upper inlet duct 235 in the wellhead 16.

The operation of the mechanism 9 of the disclosed well apparatus is briefly summarized at this point. After the wellhead 16 has been installed on the casinghead assembly 20, a hole (not shown) for a string of casing 310 is drilled. This, of course, necessitates running a drill bit and drill string, not shown, through the wellhead. Since the sleeve 10 is in its protecting position (FIG. 2) and conceals the slip hanger 11, the hanger units 12 are not contacted, or otherwise damaged, by the bit or drill string as the same is lowered and raised and rotated, nor does subsequent running of the casing string damage the hanger.

After the hole, not shown, is drilled, the drill string and bit, not shown, are removed and the string of casing 310 is run into the hole (FIG. 2). Assuming that it is desired to hang the string 310 with the slip hanger 11, the main control valve 254 (FIG. 6) is opened whereupon fluid is pumped into the inlet duct 84. This pressured fluid travels into and through the channel and through the radial inlet holes 82 against the shoulder 76 of the sleeve 10 (FIG. 2) at circumferentially spaced points therearound. Such fluid pressure against the protecting sleeve thrusts it into its exposing position (FIG. 3) where it engages with the stop ring 100.

With the protecting sleeve 10 in its exposing position (FIG. 3), fluid pressure is automatically transmitted from the lower chamber 98 via the groove 74 into the mouth 88 of the outlet duct 86 and through the duct 86 into the pilot inlet 275 of the actuator control valve 258. The actuator control valve is thereby opened and passes fluid from the outlet of the pum 252 to the inlet bores 132 of all of the actuators 112 and to the main inlet 272 of the first mandrel control valve 259. The hanger units 12 are thereupon thrust into their hanging positions (FIG. 3) with the junk ring segments 16% strik1ng the casing string 310 to be hung but continuing to rest on the lower seat 42. In this hanging position of the units, it is to be noted that the units form a substantially continuous annular hanger about the casing string with adjacent seals 166 in contact. The units are concentric with the passageway 32 and thus center the casing strlng therein in their hanging positions.

When all of the hanger units 12 are in their hanging positions, fluid pressure is automatically transmitted from the cylinders 114 (FIG. 6) through the by-pass lines 302 to the pilot inlets 275 of all of the mandrel control valves 259-262. Thus, pressure from the pump 252 is transmitted through the serially connected mandrel control valves to the inlet duct 235, and this pressure is applied against the upper end face 199 of the retaining mandrel 197. The mandrel is thereby thrust down into its retaining position (FIG. 3) wherein the mandrels mating surface 204 engages the mating surface 171 of the hanger 11 and wherein the mandrel is held by projection of the dogs 222 under the radial shoulder 46. In its retaining position, the mandrel forces the bowl segments 170 inward and downward, thereby at least partially energizing the seals 166. Furthermore, the mandrel is wedged between the hanger and the wellhead so as to dependably retain the hanger in its hanging position.

The string of casing 310 is then lowered slightly carrying the slips 172 downward a short distance along the bowl segments 170, thereby shearing the pins 178, and applying greater downward pressure to the segments and seals. The slips are thereby constricted tightly about the casing string whereupon the string is hung in the slip hanger. In addition, downward movement of the casing causes further energization of the seals 166 into circumferentially continuous fluid-tight engagement with the casing string and with the mandrel 197.

After the casing string 310 is hung in the manner described, it is cut off to provide an upper end 311. Furthermore, an annular secondary seal and bit guide 315 is landed on the upper seat 58 (FIG. 3) and projects down between the guide sleeve 185 and the casing string. Outer seals 316 and inner seals 317 are provided in the secondary seal and bit guide and are in sealing engagement respectively with the wellhead 16 and with the casing string. A snap ring 318 is mounted on the lower end of the secondary seal and bit guide for latching engagement under the lower edge 187 of the guide sleeve.

From the foregoing, it will be evident that a remotely controllable pipe hanging mechanism has been described. The reservoir 250, the pump 252 and the valve 254 are normally positioned at a location remote from the wellhead 16, usually on a vessel at the surface of the water above the well. When fluid pressure is applied in the main supply line 256, the operation of the mechanism is automatic and sequential, that is, the protecting sleeve 10 first moves to an exposing position, the hanger units 12 then move to their casing hanging positions, and the mandrel 197 then moves to its retaining position, it being noted that the mandrel cannot move to its retaining position until all of the hanger units are in their hanging positions. The subject mechanism, therefore, protects the slip hanger 11 until it is desired to use the same, then operates by remote control to bring the slip hanger to a hanging position, and thereafter dependably retains the slip hanger in its hanging position.

Although a preferred embodiment of the present invention has been shown and described it will be understood that various changes and modifications may be made in the details thereof with-out departing from the spirit and the scope of the appended claims.

Having thus described the invention, what is claimed to be new and what is desired to be secured by Letters Patent is:

1. In a well apparatus, a head providing a passageway therethrough, pipe hanging means supported by the head in said passageway for movement inwardly thereof from a retracted position to a pipe hanging position where said hanging means is closer to the axis of the passageway than in said retracted position, sleeve means mounted in said head in said passageway for movement from a protecting position wherein said sleeve means confronts said hanging means in its retracted position to an exposing position wherein said sleeve means is displaced from said hanging means, said sleeve means being movable in said head means, expansible chamber means defined by said sleeve and said head, and means for introducing fluid pressure into said chamber means to move said sleeve means from its protecting position to its retracted position to permit said hanging means to move from its retracted position to its pipe hanging position.

2. The apparatus of claim 1 further including means responsive to movement of said sleeve into its exposing position for moving said hanging means into its pipe hanging position.

3. The apparatus of claim 1 wherein said head is formed with an abutment disposed transversely of said passageway, said sleeve means includes a longitudinal shank and a transverse shoulder, said sleeve means being movable between a protecting position with said shoulder close to said abutment and an exposing position with said shoulder spaced farther from said abutment, fluid operable means mounting said hanging means in said passageway for movement from a retracted position wherein said hanging means is between said sleeve means and said head when the sleeve means is in its protecting position and a hanging position wherein said hanging means is spaced inward of the sleeve means when the latter is in its exposing position, said shank of said sleeve means including means for enabling transmission of fluid pressure from said expansible chamber means to said fluid operable means when said sleeve means is in its exposing position.

4. The apparatus of claim 3 wherein said enabling means is a groove in said shank that communicates with said expansible chamber when said sleeve means is in its exposing position.

5. In a well apparatus for hanging well pipe, a tubular head member adapted to receive such pipe, a plurality of hanger units posiitoned within said head member in circumferentially spaced relation therearound and around the pipe in the head member, means mounting said units on said head member for movement from retracted positions relatively adjacent to said head member inwardly to casing hanging positions wherein said units form a substantially continuous hanger concentric with said head member, circumferentially adjacent hanger units being in contact with each other in said'hanging positions, means i for positively moving said units from retracted positions to hanging positions, said units having means for engaging said pipe and suspending it from the head member in said hanging positions of the units, and means separate from said head member and bearing against said hanger units for locking said hanger units in their hanging positions.

6. The apparatus of claim 5 wherein a guide sleeve is mounted in said head in circumferentially spaced relation thereto and in surrounding relation to said pipe, wherein said locking means is an annular mandrel surrounding said sleeve and slidable axially thereof from said retracted position to said locking position, and

9 wherein tubular sealing means is supported in and by said head member and projects between said sleeve and pipe in sealing engagement therewith.

7. The apparatus of claim wherein said mounting means are a plurality of cylinders, said head member having bores receiving said cylinders, said mounting means also having pistons individually connected to the hanger units and slidably fitted in said cylinders for movement axially thereof thereby to move said hanger units from their retracted positions to their hanging positions.

8. The apparatus of claim 7 wherein said locking means is also separate from said mounting means and is movable from retracted position into its locking position, and including fluid means connected to said cylinders and to said head member for applying fluid pressure in said cylinders thereby to move said hanger units into their hanging positions and for thereafter forcing said locking means into its locking position.

9. In a well apparatus including a head providing passageway therethrough, a pipe hanger including a plurality of hanger units mounted in said passageway in generally circular formation, means supporting said hanger in said head for movement from an outer diametrically expanded position wherein the units are circumferentially spaced from each other about the axis of the passageway to an inner diametrically contracted hanging position wherein adjacent units are in engagement, a sleeve movably mounted in said passageway means to move said sleeve axially from a position inwardly confronting said hanger units in their outer position to a position displaced from said units, an annular mandrel supported in said passageway in a retracted position away from said hanger, means to move said mandrel to a hanger retaining position wedged between said head and said units in their inner position and fluid pressure means interconnecting said sleeve and mandrel moving means for sequentially moving said sleeve from its confronting position to its displaced position, said units from their outer position to their inner position, and said mandrel from its retracted position to its retaining position.

10. The well apparatus of claim 9, each of said hanger units includes a base element, a resiliently compressible and expansible seal element positioned on the base element, a bowl element overlying said seal element, and a slip mounted on said bowl element; said mandrel in said wedged position compressing said seal element between said bowl and base elements.

11. The apparatus of claim 10 including elongated hanger mounting members slidably mounted in said head member for movement transversely of said axis, said hanger unit being supported on said mounting member, said mandrel having a plurality of notches for receiving said mounting members when said mandrel is wedged between said hanger units and said head.

12. The apparatus of claim 10 wherein said head has a supporting seat obliquely related to the axis of the passageway, and wherein said base element of the hanger unit is slidably rested on said seat.

13. In a well apparatus, a wellhead providing a passageway therethrough including axially spaced first and second portions of predetermined diameter and an intermediate portion having a diameter greater than and between said first and second portions; a sleeve mounted in said first portion for axial movement between a protecting position projecting into said intermediate portion and an exposing position substantially entirely withdrawn into said first portion of the passageway; fluid cylinders mounted in said wellhead; pistons in said cylinders and projecting into said intermediate portion of the passageway, said pistons being movable farther into said passageway in response to fluid pressure introduced into said cylinders; slip hanger units individually mounted on said pistons and being movable with said pistons from .outer retracted positions, where said units are circumferentially spaced about said sleeve, to inner hanging position where all of said units are assembled into circumferentially continuous annular formation; annular mandrel means axially slidably fitted in said second portion of the passageway for movement from a retracted position displaced lengthwise of the passageway from said slip units to a retaining position in said intermediate portion and wedged between said slip units and said wellhead when said slip units are in their inner positions; and fluid circuit means connected to said wellhead and to said cylinders for sequentially moving said sleeve from its protecting position to its exposing position, said units from their outer positions to their inner positions, and said mandrel means from its retracted position to its retaining position.

14. The well apparatus of claim 13 including means for latching said mandrel means in its retaining position.

15. In a well apparatus of claim 13 wherein said wellhead has shoulder means projecting substantially radially between the second and intermediate portions of said passageway, a dog mounted in said mandrel means for radial movement between a latching position projecting outward from said mandrel means and a retracted position withdrawn inward from said latching position, and spring means in said mandrel means urging said dog into its latching position, said spring means urging said dog against the wellhead when the mandrel means is retracted and into engagement with said shoulder means when the mandrel means is in retaining position.

16. In a well mechanism comprising a tubular head having a passageway therethrough, a pipe hanger mounted in the passageway for movement transversely thereof from an outer retracted position to an inner hanging position radially spaced from the head, said hanger and head defining a space therebetween in said hanging position, fluid actuating means for moving said hanger from its outer to its inner position, said actuating means having inlet means and an outlet and means establishing fluid communication between said inlet means and outlet only in said hanging position of the hanger, a sleeve mounted in said passageway for movement axially thereof from a protecting position confronting said hanger, when the latter is in its outer position, to a retracted position, said head having first inlet means opening into said passageway adjacent to said sleeve for introducing fluid to move said sleeve from protecting position to retracted position, said head also having an outlet, said sleeve having means establishing fluid communication between said inlet means and outlet of the head in the retracted position of the sleeve, a mandrel mounted in said passageway for movement from a retracted position to a retaining position in the space between said head and said hanger when the latter is in its hanging position, said head having second inlet means opening into said passageway adjacent to said mandrel for introducing fluid to move said mandrel from retracted to retaining position, and a fluid system connected to all of said inlet means for initially applying fluid pressure to said sleeve to move the same to retracted position, thence for applying fluid pressure to said actuating means through the outlet of the head, and thence for applying fluid pressure to said mandrel through the outlet of said actuating means to move the mandrel to its retaining position.

17. The mechanism of claim 16 wherein there are a plurality of hangers and associated actuating means and wherein said fluid system applies pressure to said mandrel only after all of said hangers are in their inner positions.

18. The mechanism of claim 17 wherein said system includes check valves individually connected to the outlets of said actuating means and also connected in series with each other and with the outlet in the head and said second inlet means whereby fluid pressure is transmitted from said outlet in the head to said second inlet means only after all of the associated inlet means and outlets of said actuating means are in communication.

19. In a well apparatus, wall means having an annular portion surrounding an upstanding passageway and a cylinder :portion extending transversely in said annular portion in oblique relation to said passageway, a piston mounted in said cylinder portion and projecting into said passageway, said piston being gravitationally movable in said obliquely disposed cylinder portion from an outer retracted position to an inner position projecting farther into said passageway than when in said retracted position, frangible means interconnecting said piston and said cylinder portion and yieldably retaining said piston in its outer position, and pipe-hanging means mounted on said piston for movement therewith.

20. The apparatus of claim 19 including fluid means connected to said cylinder for applying fluid pressure against said piston thereby to break said frangible means and to force said piston into its inner position.

21. The apparatus of claim 19 wherein said cylinder portion includes a tube receiving said piston and a cap connected to said tube in confronting relation to said piston, and wherein said frangible means interconnects said piston and said cap.

22. The apparatus of claim 21 wherein said cap includes a bore opening into said tube, wherein said frangible means is a screw having a solid portion connected to said piston and a coupling portion fitted in the bore of said cap, said coupling portion having a duct opening into the bore of said cap, and wherein said fluid means is connected to the bore of said cap for applying fluid pressure through said duct and against said solid portion of the screw.

23. A fluid actuator comprising wall means providing a bore, a cylinder including a tube fitted in said bore and a block outside of said bore, said wall means and cylinder providing a fluid conducting space therebetween, a piston movable in said tube from a first position adjacent to said block to a second position farther away from said block, said block having an inlet bore communicating with the tube and an outlet passage communicating with said space, and said tube having an outlet port establishing communication with said space only when said piston is in its second position.

24. The fluid actuator of claim 23 wherein said tubular portion is circumferentially spaced from said wall means thereby to provide said fluid passage.

25. The actuator of claim 23 including a frangible screw having an inner externally threaded solid portion threaded into the piston and an outer portion threaded into the inlet bore of the head and providing a duct extending axially thereof, said duct having an open end opening into said inlet bore and a closed end provided by said solid inner portion of the screw.

References Cited UNITED STATES PATENTS 2,008,128 7/1935 Condon 9l402 X 2,291,143 7/ 1942 Brown 285147 X 2,542,302 2/1951 Barker 285- 2,572,318 10/1951 Church 24263.5 2,897,895 8/1959 Ortloff 285-145 X 2,962,096 11/1960 Knox 285--315 X 3,017,931 1/1962 Jackson 285-144 X 3,119,298 1/1964 Brown 2852 X 3,137,348 6/1964 Ahlstone 285144 X 3,163,220 12/1964 Haeber et al.

3,209,829 10/1965 Haeber 285-145 3,266,823 8/1966 Wood et al 285-144 CARL W. TOMLIN, Primary Examiner.

I D. W. AROLA, S. R. MILLER, Assistant Examiners. 

1. IN A WELL APPARATUS, A HEAD PROVIDING A PASSAGEWAY THERETHROUGH, PIPE HANGING MEANS SUPPORTED BY THE HEAD IN SAID PASSAGEWAY FOR MOVEMENT INWARDLY THEREOF FROM A RETRACTED POSITION TO A PIPE HANGING POSITION WHERE SAID HANGING MEANS IS CLOSER TO THE AXIS OF THE PASSAGEWAY THAN IN SAID RETRACTED POSITION, SLEEVE MEANS MOUNTED IN SAID HEAD IN SAID PASSAGEWAY FOR MOVEMENT FROM A PROTECTING POSITION WHEREIN SAID SLEEVE MEANS CONFRONTS SAID HANGING MEANS IN ITS RETRACTED POSITION TO AN EXPOSING POSITION WHEREIN SAID SLEEVE MEANS IS DISPLACED FROM SAID HANGING MEANS, SAID SLEEVE MEANS BEING MOVABLE IN SAID HEAD MEANS, EXPANSIBLE CHAMBER MEANS DEFINED BY SAID SLEEVE AND SAID HEAD, AND MEANS FOR INTRODUCING FLUID PRESSURE INTO SAID CHAMBER MEANS TO MOVE SAID SLEEVE MEANS FROM ITS PROTECTING POSITION TO ITS RETRACTED POSITION TO PERMIT SAID HANGING MEANS TO MOVE FROM ITS RETRACTED POSITION TO ITS PIPE HANGING POSITION. 